1) Fast executables 2) No runtime requirement 3) Good ecosystem (for Scheme) 4) Good ffi (though I'd prefer a great ecosystem).
That's basically all I want. I also kept going back to Gambit but it fails at #3 which Chicken seems not to.
Is there a gotcha for Chicken that I'm not remembering? Like how Racket has a slow startup cost, Chicken doesn't seem to have that (from my testing). I think Gambit is probably still faster but not by much (I could be wrong here).